Right on man, appreciate all the advice from you and the other fellow growers. I went with the Cmh because I heard nothing but good stuff, but It's been over 10 years since I've grown and I feel lost at times, my 1st set up was a 7x8x8 room I built in my garage with 1000w Hps, recirculating drip 6" rockwool in a 4x4 tray, 4 trainwrecks (Original clone only) and 5 skunk #1's. Height wasn't an issue, I vegged with the 1000w Hps with no problem and harvested 1.75 pounds. But now I'm using a 5x5x80 grow tent and there seems to be a lot more involved (temperature wise) and using the Cmh is a lot different from Hps. I raised the tent 12" high off the floor on a platform and the grow tray stand is 16" high off the floor of the tent so that I get proper drainage outside the tent to my reservoir. Right now my light is as high as it can go and I have exactly 38" between the light and the top of the plants. It's been 7 days since I started the grow and my plants have grown 4". I'll attach some photos of one of the clones from day 1, 4, and 7. Also here's the link for my grow journal I started on RUI.
630w CMH sog hydro grow | Rollitup
https://www.rollitup.org/t/630w-cmh-sog-hydro-grow.975074/